1. Field of Invention
The present invention relates to a circuit breaking device and, in particular, to a circuit breaking device which, when checking and maintaining an electric car, a hybrid car or a similar car which includes a high-voltage circuit used to drive a motor, can cut off the circuit current of the high-voltage circuit temporarily.
2. Related Art
In recent years, when checking and maintaining a car such as an electric car, a hybrid car or a similar car which is in the spotlight as a low-pollution car and includes a high-voltage circuit used to drive a motor, in order to prevent an operator from getting an electric shock, it is necessary to cut off the circuit current of the high-voltage circuit temporarily.
In view of this, in a conventional electric car or the like, as a circuit breaking device for cutting off the circuit current of a high-voltage circuit temporarily, there is proposed a circuit breaking device which comprises a plug box including a circuit terminal connected to the open end of an electric circuit, and a plug main body including a short-circuit terminal and structured such that it can bring the short-circuit terminal into fit with the circuit terminal of the plug box to thereby close the electric circuit.
According to the above-mentioned conventional circuit breaking device, when checking and maintaining the electric car or the like, an operator pulls the plug main body out of the plug box completely and removes the short-circuit terminal of the plug main body from the circuit terminal of the plug box, there by being able to open the electric circuit and thus cut off the circuit current of the electric circuit.
However, in the above-mentioned conventional circuit breaking device, in a state where the plug main body is pulled out of the plug box completely in the car check and maintenance, on the plug box, there is exposed a terminal insertion hole through which the short-circuit terminal of the plug main body can be inserted. Therefore, there is a fear that the fingertips of the operator or a conductive part (a wire or the like) can be inserted into the terminal insertion hole by mistake to thereby come into contact with the circuit terminal provided within the plug box. In order to prevent the operator's fingertips or conductive part from coming into direct contact with the circuit terminal, it is necessary to work the plug box specially, with the result that the structure of the plug box is complicated.
Also, since the plug main body pulled out of the plug box is separated completely from the plug box, there is a fear that the plug main body can be lost by accident.